Strain film type three-axis closed-loop OIS motor

Abstract

The utility model relates to a strain film type three-axis closed-loop OIS motor. The motor comprises a housing, a lens carrier, a frame, an upper elastic sheet and a lower elastic sheet. A strain film is arranged on the upper elastic sheet; the strain film is arranged between the top of the lens carrier and the inner top wall of the shell and correspondingly deforms along with the movement of the lens carrier; the upper elastic sheet is respectively connected with the lens carrier and the frame; and the upper elastic sheet is electrically connected with a circuit board arranged in the shell. According to the utility model, a three-axis closed loop is realized by using the strain film and the OIS sensor, the assembly difficulty is not increased, the cost is lower, and the thickness of the strain film can be reduced in closed loop driving.

Description

Technical Field

[0001] The utility model relates to the field of optical imaging, and particularly relates to a strain film type three-axis closed-loop OIS motor. Background Art

[0002] With the rapid development of technology, electronic devices in modern society have entered a new stage. It is not difficult for us to find that many electronic products used in daily life, such as smart phones or digital cameras, already have powerful photography and video recording functions. These functions are no longer limited to professional photographic equipment, but have become increasingly popular and an indispensable part of our lives. To meet the needs of the majority of consumers, these electronic devices are also increasingly focusing on convenience and thinness in design, striving to provide rich functions while maintaining a lightweight appearance and portability.

[0003] Among these electronic devices with photography or video recording functions, the lens driving device undoubtedly plays a crucial role. It is responsible for driving the optical components in the lens to move precisely, thereby realizing the functions of autofocus and optical anti-shake. When we press the shutter or video recording button, light passes through the optical components of the lens and finally focuses on the photosensitive component to form a clear and stable image.

[0004] However, the existing lens driving devices face some challenges in design. Although they usually include key components such as an OIS coil group, a magnet group, an AF coil, and a carrier for mounting the lens, the cooperative design of these components is quite complex. Especially the coil group and the magnet group, which are often stacked axially, not only increase the assembly difficulty but also make the overall thickness of the device larger axially. Such a design not only affects the overall aesthetics of the electronic product but also is not conducive to achieving the goal of thinness.

[0005] In addition, most of the existing lens driving devices adopt an open-loop driving method. Although this driving method is simple, it cannot sense the actual position of the lens in real time. When the environmental or structural characteristics change, the control effect may be seriously affected, resulting in a decline in image quality. Therefore, how to achieve closed-loop driving to ensure that the lens driving device can work stably and precisely under various conditions has become the key to the current technology implementation. Summary of the Utility Model

[0006] (1) Technical Problems to be Solved

[0007] To solve the above problems of the existing technology, the utility model provides a strain film type three-axis closed-loop OIS motor.

[0008] (2) Technical Solutions

[0009] To achieve the above object, the main technical solutions adopted by the present utility model include:

[0010] A strain film type three-axis closed-loop OIS motor, comprising

[0011] A housing, within which a hollow cavity is formed;

[0012] A lens carrier, arranged within the hollow cavity and movable along the optical axis direction; an AF drive coil is provided outside the lens carrier;

[0013] A frame, arranged within the hollow cavity and movable perpendicular to the optical axis direction; the lens carrier is sleeved within the frame; a plurality of drive magnets are provided on the frame;

[0014] An upper elastic sheet, on which a strain film is provided; the strain film is arranged between the top of the lens carrier and the inner top wall of the housing and generates corresponding deformation as the lens carrier moves; the upper elastic sheet is respectively connected to the lens carrier and the frame; the upper elastic sheet is electrically connected to a circuit board arranged within the housing;

[0015] An OIS drive coil is provided within the housing.

[0016] Further, the housing includes an upper cover and a base; the bottom of the upper cover is open and fixedly connected to the base to form a hollow cavity inside; the OIS drive coil is arranged on the upper end surface of the base.

[0017] Further, a magnet mounting groove is provided on the inner side of the bottom end of the frame; the drive magnets are fixed within the magnet mounting groove; four drive magnets are provided.

[0018] Further, the upper elastic sheet is connected to the circuit board through a connecting member; the circuit board is arranged on the base.

[0019] Further, the outer side of the upper elastic sheet is connected to the frame, and the inner side is connected to the lens carrier.

[0020] Further, the upper elastic sheet is composed of several independent upper elastic branches; the inner side of each upper elastic branch is connected to the lens carrier, and the outer side is connected to the frame; the end of each upper elastic branch is connected to the circuit board on the base through a connecting member; the strain film is at least arranged at the part where the upper elastic branch is connected to the lens carrier to generate corresponding deformation as the lens carrier moves.

[0021] Further, an OIS sensor is provided on the base.

[0022] Further, a lower elastic sheet is provided between the lens carrier and the base; the lower elastic sheet is respectively connected to the frame and the lens carrier.

[0023] Furthermore, the lower elastic piece includes an integrally provided elastic piece ring and four bent chord wires arranged around the elastic piece ring.

[0024] (III) Beneficial effects

[0025] The beneficial effects of the present utility model are as follows: By using a strain film, a three-axis closed loop is achieved with the OIS sensor, without increasing the assembly difficulty and with a lower cost. The strain film can also reduce the thickness during closed-loop driving. Description of the drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0027] Figure 1 is the exploded view of the structure of the present utility model;

[0028] Figure 2 is the schematic diagram of the circuit connection of the present utility model;

[0029] Figure 3 is the schematic diagram of a Wheatstone bridge;

[0030] Figure 4 is the circuit diagram of LC898217XC;

[0031] Figure 5 is the pin diagram of LC898217XC;

[0032] Description of the reference numerals:

[0033] 110, base; 111, circuit board; 120, upper cover; 200, frame; 210, driving magnet; 220, OIS driving coil; 230, OIS sensor; 300, lens carrier; 310, AF driving coil; 400, upper elastic piece; 410, strain film; 420, upper elastic support piece; 430, connecting piece; 440, lower elastic piece; 441, elastic piece ring; 442, chord wire. Specific embodiments

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model. Therefore, the detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the present utility model to be protected, but merely represents the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model.

[0035] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0036] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0037] As Figure 1-2 shown, a strain film type three-axis closed-loop OIS motor includes a housing, a lens carrier 300, a frame 200, an upper elastic sheet 400, and a lower elastic sheet 440; wherein the lower elastic sheet 440 is an optional structure that is not necessary.

[0038] A hollow cavity is formed inside the housing; the housing is usually composed of a base 110 and an upper cover 120; the bottom opening of the upper cover 120 is connected to the base 110 by means of snap connection, welding, or bonding.

[0039] A frame 200 is provided in the hollow cavity, and a lens carrier 300 is sleeved inside the frame 200; an axially communicating lens through hole is provided in the middle of the upper cover 120, the base 110, and the lens carrier 300 along the optical axis direction (Z-axis) to accommodate the lens;

[0040] The frame 200 can move perpendicular to the optical axis direction in the hollow cavity, specifically, it can move along the X-axis and the Y-axis; a number of driving magnets 210 are provided on the frame 200; in one embodiment, a magnet mounting groove is provided inside the bottom end of the frame 200, and the driving magnets 210 are fixed in the magnet mounting grooves, and four magnet mounting grooves are respectively arranged along the four sides of the frame 200;

[0041] The OIS driving coil 220 is provided on the upper end surface of the base 110; the frame 200 is also located on the upper end of the base 110, and the frame 200 can move in the X-axis and Y-axis directions on the base 110; under the action of the OIS driving coil 220 and the corresponding driving magnets 210, the frame 200 together with the driving magnets 210 and the lens carrier 300 will move in the X-axis and Y-axis directions in the hollow cavity;

[0042] An AF driving coil 310 is provided on the outer side of the lens carrier 300, and the lens carrier 300 is located inside the frame 200; the lens carrier 300 can move along the optical axis direction (Z-axis direction) in the hollow cavity, and the optical axis direction is the direction parallel to the Z-axis; the movement of the lens carrier 300 is a movement in the Z-axis direction relative to the inside of the frame 200; under the action of the AF driving coil 310 and the driving magnets 210, the lens carrier 300 will move in the Z-axis direction relative to the frame 200; it should be noted that the lens (not shown in the figure) is installed in the lens carrier 300, so the above movement will drive the lens to move, thereby realizing the three-axis movement operation of the lens;

[0043] The upper elastic sheet 400 is provided with a strain film 410. The strain film 410 is arranged between the top of the lens carrier 300 and the inner top wall of the housing and generates corresponding deformation as the lens carrier 300 moves; the upper elastic sheet 400 is respectively connected to the lens carrier 300 and the frame 200; the upper elastic sheet 400 is electrically connected to the circuit board 111 arranged in the housing; when the strain film 410 generates deformation, the resistance value of the strain film 410 will change accordingly, so that the output voltage of the strain film 410 changes accordingly, and the output voltage signal is linear. Therefore, the output voltage of the strain film 410 can reflect the movement track of the lens carrier 300. By using the strain film 410 to sense the movement track of the lens carrier 300, the effect of a closed-loop motor can be achieved. Compared with the existing structure that senses the movement track of the lens carrier 300 through a Hall element and a feedback magnet, this structure senses the movement track of the lens carrier 300 through the strain film 410, which is simpler in structure, lower in cost, and can better control the thickness dimension.

[0044] In one embodiment, the upper elastic sheet 400 is electrically connected to the circuit board 111 arranged in the housing; the circuit board 111 is arranged on the base 110; the upper elastic sheet 400 is electrically connected to the circuit board 111 through a connecting member 430; the connecting member 430 is a suspension loop line, which is a flexible member and can bear tension; a lower elastic sheet 440 is arranged between the lens carrier 300 and the base 110, and the lower elastic sheet 440 is respectively connected to the frame 200 and the lens carrier 300; the lower elastic sheet 440 can play an auxiliary reset role after the lens carrier 300 moves in the Z-axis direction relative to the frame 200; the lower elastic sheet 440 includes an integrally arranged elastic sheet ring 441 and four bent chord wires 442 arranged around the elastic sheet ring 441.

[0045] In one embodiment, the upper elastic sheet 400 is composed of three independent upper elastic branches 420; the three upper elastic branches 420 are surrounded, and there is a certain distance between adjacent two upper elastic branches 420; the inner side of each upper elastic branch 420 is connected to the lens carrier 300, and the outer side is connected to the frame 200; the end of each upper elastic branch 420 is electrically connected to the circuit board 111 on the base 110 through a connecting member 430, where the connecting member 430 can be connected to one end of the upper elastic branch 420 or respectively connected to both ends; the strain film 410 is at least coated on the part where the upper elastic branch 420 is connected to the lens carrier 300 to generate corresponding deformation as the lens carrier 300 moves.

[0046] In another embodiment, the strain film 410 can be entirely coated on the upper surface of the upper elastic branch 420.

[0047] In another embodiment, the strain film 410 is coated, partially coated, on the upper surface of the upper elastic support piece 420, and the area of the upper elastic support piece 420 coated with the strain film 410 does not coincide at least partially with the connection part of the upper elastic support piece 420 and the lens carrier 300; the strain film 410 in the non-coincident part can deform better with the movement of the lens carrier 300.

[0048] In another embodiment, the strain film 410 is only coated on the upper surface of one upper elastic support piece 420.

[0049] In one embodiment, the structure of the upper elastic piece 400 is connected to the lens carrier 300, the frame 200, and the base 110 at the same time. Under the elastic action of the upper elastic piece 400, when the frame 200 moves relative to the base 110 in the X-axis and Y-axis directions or when the lens carrier 300 moves relative to the frame 200 in the Z-axis direction, the upper elastic piece 400 can play an auxiliary reset role, so that the structure of the lower elastic piece 440 becomes an unnecessary optional structure; the upper elastic piece 400 is connected to the base 110 through a connecting piece 430; the connecting piece 430 is a rigid piece so as to be able to play a supporting role and ensure the relative distance at the connection between the upper elastic piece 400 and the base 110, so as to be able to realize the reset of the frame 200 and the lens carrier 300.

[0050] In one embodiment, two OIS sensors 230 are provided on the base 110, which respectively sense the movement trajectories of the frame 200 in the X-axis and Y-axis directions; the OIS sensor 230 is a Hall sensor.

[0051] As Figure 2-5 shown, a driving IC is found on the market; taking LC898217XC as an example, LC898217XC (including 11-bit ADC and position sensing signal input OPINP / OPINM & 100X clamping signal amplification) can distinguish 30 μV, which is equivalent to a deformation height of 0.16 μm on an 8-mm-long strain film. Figure 4 The position sensor in

[0052] The resistance of the strain film 410 on the upper elastic piece 400 is R1, the value of ΔR1 is proportional to the deformation amount of the strain film 410, and multiple resistors are externally connected to form a Wheatstone bridge to output an induced voltage, which is proportional to the deformation amount of the upper elastic piece 400.

[0053] Among them, the Wheatstone bridge satisfies R1 = R2, R3 = R4.

[0054]

[0055] A single-arm Wheatstone bridge means that only one resistor changes, such as the resistor R1 in Figure 2-3 , while the other three resistors remain unchanged;

[0056] The connection circuit of the strain film 410 is as shown in Figure 2 . The resistor R1+ΔR1 of the strain film 410 is welded to the outer string of the upper elastic piece 400; the outer string of the upper elastic piece 400 is welded to the connecting piece 430; the connecting piece 430 is welded to the metal circuit (circuit board 111) inside the base 110; the resistor R1+ΔR1 of the strain film 410 and the external resistors R2 / R3 / R4 form a Wheatstone bridge, and the circuit connection of the Wheatstone bridge to the IC is shown in 2-5.

[0057] In the present utility model, the X / Y axes rely on the OIS sensor 230 to sense the position change, and the Z axis relies on the deformation of the strain film 410 to sense the position change, realizing a three-axis closed loop;

[0058] The above are only embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in the relevant technical fields, shall be similarly included in the patent protection scope of the present utility model.

Claims

1. A strain film type three-axis closed-loop OIS motor, characterized in that: include a shell having a hollow cavity formed therein; A lens carrier (300) is arranged in the hollow cavity and can move along the optical axis; an AF driving coil (310) is arranged outside the lens carrier (300); A frame (200) is arranged in the hollow cavity and can move perpendicularly to the optical axis; the lens carrier (300) is sleeved in the frame (200); and a plurality of driving magnets (210) are arranged on the frame (200); An upper spring sheet (400), wherein a strain film (410) is provided on the upper spring sheet (400); the strain film (410) is arranged between the top of the lens carrier (300) and the inner top wall of the shell and generates corresponding deformation as the lens carrier (300) moves; the upper spring sheet (400) is respectively connected to the lens carrier (300) and the frame (200); the upper spring sheet (400) is electrically connected to a circuit board (111) arranged in the shell; An OIS driving coil (220) is arranged in the shell.

2. The strain film type three-axis closed-loop OIS motor according to claim 1, characterized in that: The shell comprises an upper cover (120) and a base (110); the bottom opening of the upper cover (120) is fixedly connected to the base (110) to form a hollow cavity inside; and the OIS driving coil (220) is arranged on the upper end surface of the base (110).

3. The strain film type three-axis closed-loop OIS motor according to claim 1, characterized in that: A magnet installation groove is provided on the inner side of the bottom end of the frame (200); the driving magnet (210) is fixed in the magnet installation groove; four driving magnets (210) are provided.

4. The strain film type three-axis closed-loop OIS motor according to claim 2, characterized in that: The upper spring sheet (400) is connected to the circuit board (111) via a connecting piece (430); the circuit board (111) is arranged on the base (110).

5. The strain film type three-axis closed-loop OIS motor according to claim 2, characterized in that: The upper spring sheet (400) is connected to the frame (200) on the outside and to the lens carrier (300) on the inside.

6. The strain film type three-axis closed-loop OIS motor according to claim 2, characterized in that: The upper elastic sheet (400) comprises a plurality of independent upper elastic support sheets (420); the inner side of each upper elastic support sheet (420) is connected to the lens carrier (300), and the outer side is connected to the frame (200); the end of each upper elastic support sheet (420) is connected to the circuit board (111) on the base (110) through a connecting piece (430); the strain film (410) is at least arranged at the location where the upper elastic support sheet (420) is connected to the lens carrier (300) so as to generate corresponding deformation as the lens carrier (300) moves.

7. The strain film type three-axis closed-loop OIS motor according to claim 2, characterized in that: An OIS sensor (230) is provided on the base (110).

8. The strain film type three-axis closed-loop OIS motor according to claim 1, characterized in that: A lower spring sheet (440) is provided between the lens carrier (300) and the base (110); the lower spring sheet (440) is respectively connected to the frame (200) and the lens carrier (300).

9. The strain film type three-axis closed-loop OIS motor according to claim 8, characterized in that: The lower spring piece (440) comprises an integral spring piece ring (441) and four bent strings (442) arranged around the spring piece ring (441).

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